ROG Rampage VI Apex shows simple tweaks can tame X299 VRMs

Roman "der8auer" Hartung recently cast shade on a handful of motherboards based on Intel's X299 chipset. According to the extreme overclocker, the boards' voltage-regulation circuits can hit temperatures as high as 105° C with a Core i9-7900X overclocked to a relatively modest 4.6 GHz. 105° C is the range in which many such circuits will begin to throttle the system for safety. Hartung also criticized the single eight-pin EPS +12V power connectors and current VRM heatsink designs on many X299 boards.

Now Hartung is back in a new video discussing how some simple changes on Asus' ROG Rampage VI Apex motherboard avoid these temperature and power limits. While his comments reflect his feelings about Asus' overclocking-focused board specifically, the broader takeaway is that relatively simple improvements could be incorporated into X299 boards from all manufacturers to improve VRM temperatures and performance headroom.

In particular, Hartung appreciates the dual eight-pin EPS +12V connectors, high-quality inductors, and the beefy heatsink attached to the VRM components on the Apex. The VRM heatsink is of particular interest. Hartung says Asus has revised the cooler since the board was first shown off at Computex, and it now features a finned primary heatsink over the board's inductors and MOSFETs. That primary heatsink connects to another, larger hunk of aluminum perched over the rear I/O ports using a single heatpipe. The VRM cooler also has threaded holes for attaching a fan to provide additional airflow to the heat-producing components. Hartung is somewhat less enthused about a small slab of aluminum strapped to a trio of capacitors on the reverse side of the motherboard.

The professional overclocker presents test results that show his i9-7900X-plus-Rampage-VI-Apex test system stable with a 4.9 GHz overclock. The CPU was pulling a hair-raising 340W from the VRMs in this setup, but the system wasn't throttling due to the temperatures of that circuitry. The processor was limited instead by the thermal dissipation capacity of Hartung's liquid cooler. Attaching a small fan to the VRM heatsink reduced VRM temperatures from a hot-but-within-component-specification 103° C to a much-less-alarming 87° C under these conditions.

This older photo of the Apex lacks the heatsink fins that will presumably be found in the retail model.

The Asus ROG Rampage VI Apex is sure to be an overclocker's delight when it is released to the public, but those looking to build a more productivity-focused X299 system might not appreciate the board's four DIMM slots instead of the usual eight. We can only hope that all motherboard manufacturers incorporate similar design changes into the VRM heatsinks of their X299 products soon.